Dr. M.P.P.U Chulasiri, N.S.Gunawardena, & G.A.C. De Silva. (2016). Prevalence of smoking among adult males in Colombo District, Sri Lanka. Asian Pacific Journal of Health Sciences, 3(4(S), 73–80. https://doi.org/10.21276/apjhs.2016.3.4s.12